The city is centered on a 335 meters high (1,099 feet) mesa of andesite which formed its acropolis. This mesa falls away sharply on the north, west, and east sides, but three natural terraces on the south side provide a route up to the top. To the west of the acropolis, the Selinus River (modern Bergamaçay) flows through the city, while the Ketios river (modern Kestelçay) passes by to the east.

circa

Trajaneum: Temple for Trajan and Zeus Philios
The construction of the temple was started under the ROman emperor Trajan (98-117 CE) and then enlarged and completed under his successor Hadrian (117-138 CE). It served the cult of both rulers and Zeus, only relicts of whose colossal statues have been found. Since the Hellenistic times, the worship of rulers had been customary in the Orient and Asia Minor. As a monument of Roman domination, the Trajaneum, served to strengthen the bonds with Rome and imperial family.

The Trajaneum is the only Roman monument on the upper fortress. The temple, conceived to have a distant effect, and the lower town complemented each other in their alignment. The large site was partly obtained by levelling the rock in the side of the mountain; the steep syncline of the side of the valley was traversed by a giant substructure.

The temple was built on a high marble covered podium in the middle of this platform. In accordance with Greek traditions, the main body of the building was free standing. On three sides, it was surrounded by halls with monolithic columns and a special form of corinthian capitals; the north hall whose supporting walls cover the remaining rock, and the side halls which were subsequently added.

It is not known when the temple was destroyed. In the Middle Ages the wall facing the valley was included in the Byzantine fortifications and restored several times. Parts of the substructures were used as cisterns.

circa

Temple-sanctuary of Hera
The sanctuary of Hera Basileia ('the Queen') lay north of the upper terrace of the gymnasium. Its structure sits on two parallel terraces, the south one about 107.4 metres above sea level and the north one about 109.8 metres above sea level. The Temple of Hera sat in the middle of the upper terrace, facing to the south, with a 6-metre-wide (20 feet) exedra to the west and a building whose function is very unclear to the east. The two terraces were linked by a staircase of eleven steps around 7.5 metres wide, descending from the front of the temple.

circa

Theatre
The well-preserved Theatre of Pergamon dates from the Hellenistic period and had space for around 10,000 people, in 78 rows of seats. At a height of 36 metres, it is the steepest of all ancient theatres. The seating area (koilon) is divided horizontally by two walkways, called diazomata, and vertically by 0.75-metre-wide (2.5 feet) stairways into seven sections in the lowest part of the theatre and six in the middle and upper sections. Below the theatre is a 247-metre-long (810 feet) and up to 17.4-metre-wide (57 feet) terrace, which rested on a high retaining wall and was framed on the long side by a stoa.

circa 150 BCE

Remains of the Great Altar of Zeus
Not much remains of the Great Altar of Pergamon, and there is little to see at the original site today, but it is enough to provide a sense of the magnitude of the great shrine. And for those who have seen the altar in Berlin, it allows one to imagine what it would have looked like in its original position, standing proudly on the acropolis. On the terrace below to the south is the upper market (agora). Bounded by stoas, it contains to the west, a temple probably dedicated to Hermes, the god of Merchants.

Dedicated to Zeus and Athena, the altar was ornamented on its vast sockel with reliefs depicting the struggle of the Olympian gods and the subterranean powers. It was built by Eumenes II (197-159 BCE) in commemoration of his victoryover the Gauls in 190 BCE. The altar, ascended by means of a stairway on its western side, enclosed an offering table within a raised court bounded on three sides by colonnaded enclosure wall which itself was ornamented on the inside with reliefs depicting the legend of Telephus, the son of Heracles and Auge and forefather of the Pergamene royal family.

circa 150 BCE

Temple of Dionysus
In the 2nd century BCE, Eumenes II (probably) built a temple for Dionysus at the northern end of the theatre terrace. The marble temple sits on a podium, 4.5 metres above the level of the theatre terrace and was an Ionic prostyle temple. The pronaos was four columns wide and two columns deep and was accessed by a staircase of twenty-five steps. Only a few traces of the Hellenistic structure survive. The majority of the surviving structure derives from a reconstruction of the temple which probably took place under Caracalla, or perhaps under Hadrian.

circa

Temple of Athena
The Temple or sanctuary of Athena was dedicated to the city goddess Athena, who brings victory, and to Zeus. It was the oldest temple known in Pergamon (4th century BCE), surrounded by Doric columns, 6 to the front and rear and 10 columns on each side with a divided room inside (of which only foundations are visible today).

A double-aisled stoa with attached library was added on the northern side of the temple precinct in the same time of Eumenes II (197-159 BCE). In the main room of the library the podium and wall sockets designed to support the book shelves are visible. On the pedestal cenered in front of the northern wall of the room stood a reduced copy of Athens' famous statue of Athena Parthenos. The reputed 200,000 scrolls kept here were carried off by Anthony in 41 BCE and presented to Cleopatra.

On the eastern side of the precinct a single aisled stoa with an entrance gateway decorated with reliefs was also added in the time of Eumenes II. The single aisled stoa on the southern side was probably added later in the second century CE. Within the sanctuary court the art collections of the Pergamene kings and the votive offerings celebrating victories over the Gauls were discplayed. On the round base in the center of the stood a statue of the Roman emperor Augustus (31 BCE- 14 CE).

circa

Temple-precinct of Demeter
The Sanctuary of Demeter occupied an area of 50 x 110 metres on the middle level of the south slope of the citadel. The sanctuary was old; its activity can be traced back to the fourth century BCE. The sanctuary was entered through a Propylon from the east, which led to a courtyard surrounded by stoas on three sides. In the centre of the western half of this courtyard, stood the Ionic temple of Demeter, a straightforward Antae temple, measuring 6.45 x 12.7 metres, with a porch in the Corinthian order which was added in the time of Antoninus Pius.

The rest of the structure was of Hellenistic date, built in local marble and had a marble frieze decorated with bucrania. About 9.5 metres in front of the east-facing building, there was an altar, which was 7 metres long and 2.3 metres wide. The temple and the altar were built for Demeter by Philetaerus, his brother Eumenes, and their mother Boa.

circa

Gymnasium
A large gymnasium area was built in the 2nd century BCE on the south side of the Acropolis. It consisted of three terraces, with the main entrance at the southeast corner of the lowest terrace. The lowest and southernmost terrace is small and almost free of buildings. It is known as the Lower Gymnasium and has been identified as the boys' gymnasium. The middle terrace was around 250 metres long and 70 metres wide at the centre. On its north side there was a two-story hall. In the east part of the terrace there was a small prostyle temple in the Corinthian order. A roofed stadium, known as the Basement Stadium is located between the middle terrace and the upper terrace.